Educational Testing Service. (2021). Official guide to the toefl ibt test, sixth edition (Sixth edition.). McGraw Hill.
Chicagoスタイル(17版)引用形式Educational Testing Service. Official Guide to the Toefl Ibt Test, Sixth Edition. Sixth edition. New York: McGraw Hill, 2021.
MLA(9版)引用形式Educational Testing Service. Official Guide to the Toefl Ibt Test, Sixth Edition. Sixth edition. McGraw Hill, 2021.
警告: この引用は必ずしも正確ではありません.